Ohio State University has refunded $1 million to 20,000 summer school students after imposing a fee increase that officials had promised wouldn’t happen.

A graduate student first noticed that students had been overcharged and brought it to the attention of student government leaders. Though tuition remained the same, fees had jumped $81 – to $323 – for the summer semester.

The university pledged that tuition and fees would not increase when the institution moved from quarters to semesters last year. It kept the promise for the first two semesters under the new calendar – but mistakenly increased fees for summer.

A university spokesman said students received refunds of up to $81 as a result of the error. Student government negotiated the rebates for months.